Like every other Golden Age pianist, Ferruccio Busoni romped in the playground of transcriptions, batting around other composers’ tunes in the spirit of competitive gamesmanship. The ghosts of Liszt and Tausig were leaning over the fence watching them play. Today many of these wowsers—dated American slang for raising one’s eyebrows in amazement—sound more like transgressions than transcriptions. But Busoni was a serious Bach scholar and editor, and when it came to the music on this 2-CD set, his arrangements for piano have survived proudly.

Bach must hold the record for the most transcribed composer in history, and Busoni’s versions aren’t unique, especially in iconic works such as the Chaconne in D Minor for violin and Stokowski’s showstopper, the Toccata and Fugue in D Minor. But when you see Bach-Busoni on the program, you can rest assured that the arrangement will be sober, true to Bach’s original (not the same as being faithful to every note), and a technical tour de force. Busoni was generous with doublings, thirds, and sixths, often laying them on to the limit of pianistic technique. He avoided the vulgarity of rolled arpeggios, however. Audiences expected a blend of church and sideshow.

Holger Groschopp has undertaken an extensive project to record Busoni’s output in this genre; there’s a previous box set of four CDs covering many other composers besides Bach. This new release focuses on organ and harpsichord music, where the earlier set included some Bach violin arrangements. Fortunately, Groschopp’s program is varied and intriguing, which he details in his excellent notes, and I didn’t miss the Chaconne in D Minor, probably the most popular of Busoni’s Bach transcriptions today, leaving aside the 10 short chorale preludes used as encores. Since these two disks contain 44 tracks, I’ll confine myself to a few general comments.

First there’s the issue of organ versus piano. Busoni recognized that there are losses and gains when the organ loft is exchanged for Carnegie Hall. A piano virtuoso must work magic to create the illusion of a pipe organ’s continuous legato, its colorful voicings that mimic woodwinds and brass, and its enormous power. Two hands must also do the work of the organist’s combined hands and feet. On the plus side, the piano has one huge advantage: touch. The gradations of touch that Horowitz employs in Busoni’s arrangement of the Chorale Prelude Nun komm, der Heiden Heiland (DG) are hypnotic, and for me, more moving than what an organist can produce. Busoni’s extant piano rolls indicate that he used considerable rubato in Bach, something generally associated with Romanticism, not historical purity.

Groschopp is an established pianist in his native Berlin, with close ties to the Berlin Philharmonic and an international tour schedule (just as impressive, he also studied voice with Fischer-Dieskau). He brings technical assurance to the most difficult arrangements here, and comparison with the legendary Russian pianist Tatiana Nikolayeva is hardly to Groschopp’s disadvantage. He has chosen to imitate the evenness of an organist’s touch. He avoids crescendos and decrescendos, and maintains a steady tempo. In other words, he eschews the piano’s advantages, deployed so eloquently by Horowitz and Busoni himself.

I grant that this sort of literalism will feel more “authentic” to some listeners, but it robs this otherwise superb set of having much personality. That’s not the same as accusing Groschopp of tedium—he held my attention with a delightful range of works, from the mighty Toccata, Adagio, and Fugue in C (BWV 564) to a 24-second miniature where, as part of a suite written on the departure of a beloved brother, Bach imitates the postman’s galloping horse and tooting horn, one of the rare occasions where he wrote program music. The journey features familiar signposts in the land of Bach such as “Sleepers Awake” and “Sheep May Safely Graze.” At the end we get a polka. I’ll tease you by not revealing what that’s about.

I sat myself down to listen with the resignation of a pupil braced for a scholarly lecture, but the entire experience turned out to be fascinating. The treasure trove of Bach’s genius has tempted countless arrangers, and thanks to Busoni, Groschopp drops a shower of gold coins in our laps.